CheckIfItIsAI

GPTZero vs Winston AI

Two detectors sold to different buyers, which is what actually drives the difference in how they behave on your text.

GPTZeroWinston AI
Built forTeachers, students, publishersEducation and publishing
Detectstexttext, image
Free tierFree tier with a word cap per scan.Trial credits.
Vendor claimMarkets itself as the most widely used AI detector by user count.Advertises 99%+ accuracy and adds OCR for handwritten work.
Main weaknessScore moves noticeably on lightly edited textSubscription required beyond the trial

Which one flags more

Detectors sold to publishers (GPTZero sits closer to this end) are tuned to reject borderline text, because a missed AI draft costs the buyer more than a wrongly rejected human one. Detectors sold into education have the opposite incentive, at least in principle, because a false accusation is a serious institutional problem.

That trade-off, not model quality, explains most of the disagreement you will see when you run the same paragraph through both.

If you are choosing one to trust

More on GPTZeroMore on Winston AI